/* * Written by Manuel Bouyer . * Public domain. */ #include __FBSDID("$FreeBSD$"); #if defined(LIBC_SCCS) && !defined(lint) static char *rcsid = "$NetBSD: bswap32.c,v 1.1 1997/10/09 15:42:33 bouyer Exp $"; static char *rcsid = "$NetBSD: bswap64.c,v 1.3 2009/03/16 05:59:21 cegger Exp $"; #endif #include #undef bswap32 #undef bswap64 u_int32_t bswap32(u_int32_t x); u_int64_t bswap64(u_int64_t x); u_int32_t bswap32(u_int32_t x) { return ((x << 24) & 0xff000000 ) | ((x << 8) & 0x00ff0000 ) | ((x >> 8) & 0x0000ff00 ) | ((x >> 24) & 0x000000ff ); } u_int64_t bswap64(u_int64_t x) { #ifdef __LP64__ /* * Assume we have wide enough registers to do it without touching * memory. */ return ( (x << 56) & 0xff00000000000000UL ) | ( (x << 40) & 0x00ff000000000000UL ) | ( (x << 24) & 0x0000ff0000000000UL ) | ( (x << 8) & 0x000000ff00000000UL ) | ( (x >> 8) & 0x00000000ff000000UL ) | ( (x >> 24) & 0x0000000000ff0000UL ) | ( (x >> 40) & 0x000000000000ff00UL ) | ( (x >> 56) & 0x00000000000000ffUL ); #else /* * Split the operation in two 32bit steps. */ u_int32_t tl, th; th = bswap32((u_int32_t)(x & 0x00000000ffffffffULL)); tl = bswap32((u_int32_t)((x >> 32) & 0x00000000ffffffffULL)); return ((u_int64_t)th << 32) | tl; #endif }